It is widely known that yogurt contains potent ingredients that are beneficial to overall human health and well-being. Over the centuries and in many regions of the world, yogurt has been and remains an integral and nourishing dietary staple. It is particularly beneficial to digestion and a healthy digestive tract.
Yogurt is created from milk using a heat fermentation process that incorporates the use of certain bacteria to effectively curdle the milk into a more concentrated and thick form. After the fermentation process is complete, some of the bacterial cultures usually survive. They remain in the yogurt providing considerable benefits upon ingestion. It is known that such “probiotic” bacteria themselves aid in digestion, counter the detrimental effects of non-beneficial bacteria and prevent certain kinds of digestive problems. It is further known that certain probiotic material can be used to create yogurt from milk. In addition, most known nutritional yogurt products are often supplemented with other live, active and beneficial, probiotic bacteria.
Yogurt can be used topically on hair in certain ways with considerable benefit. See U.S. Pat. No. 4,268,500 to Cloninger. Much like the milk from which yogurt is derived, yogurt contains particular proteins and a significant amount of lactose. In addition, both yogurt and milk contain emollient properties that contribute to healthy and attractive hair.
Two proteins which exist in yogurt and are likely to be responsible for its benefits to hair are casein and whey. Casein is present in yogurt as a by-product of the fermentation by the lactic acid-producing cultures (William Helferich and Dennis Westhoff in All About Yogurt, Prentice Hall, Inc. NJ, 1980). Casein has structural similarities with fibrinogen aside from of the fact that both are proteins with different physiological functions. While casein forms polymeric globules (micelles), fibrinogen is a fibrous polymer. An analogy between fibrinogen and casein has been reported by Jolles P., et al. in Analogy Between Fibrinogen and Casein and Effect of an undecapeptide isolated from kappa-casein on platelet function. Europ. J. Biochem. 158, 379-82. Fibrinogen produces molecular aggregation and the formation of a protective coating over damaged cells. Fibrinogen is a fibrous protein; it is stringy, tough and insoluble in water. Casein is a globular protein; it has a spherical shape. Alpha-keratin, the protein in hair and nails, has an alpha-helix structure. Casein and fibrinogen are similar in that fibrinogen is composed mostly of alpha-keratin, while the secondary structure of casein involves both alpha-helix and beta-sheet shapes. As healing and restorative processes progress, fibrinogens specifically form covalent bonds between the fibrin monomers. Casein present in yogurt could produce the same effect (formation of covalent bonds) due to the presence of the alpha-helix and beta-sheets shapes present in its secondary structure. Casein is a mixture of several similar phosphoproteins: alpha, beta, lambda and kappa-casein, all of which contain some serine side chains combined with phosphoric acid.
If we compare milk to yogurt, milk contains unprecipitated casein, while yogurt's casein is precipitated. Thus the number of peptides present in milk is much less than the number of peptides present in yogurt. Therefore, contrary to widespread industry assertions, the number of kappa-casein peptides present in milk are unlikely to deliver significant conditioning effects. Further, another difference between casein present in milk and precipitated casein in yogurt is the ability to form aggregates in the presence of charged surfaces. Casein in milk at pH 6-7, contains charged surfaces (chiefly negative charged phosphoserine residues) which repel each other. However, reduction of the pH in casein in yogurt to a pH of less than 5, reduces the ionization of serine phosphate residues and encourages agglomeration. Agglomeration is the first step leading to intermolecular and intramolecular cross links.
Whey is another protein found in milk and yogurt. Whey protein is rich in certain amino acids and low in fat. The key amino acids, the branched chain amino acids (e.g. leucine, valine and isoleucine) and cysteine can be found in relatively high amounts in whey protein (up to 3 g/100 g of protein). Whey proteins can differ dramatically from one another depending on the processing method and the total protein content. For example, whey protein can exist as simple whey powder (30% or less total protein content), whey protein concentrate (30-85% protein) or whey protein isolate (90% or higher protein content).
Whey protein is composed of alpha-lactalbumin, betta-lactoglobulin, serum albumin, immunoglobulins and protease peptones. Betta-lactoglobulin (BLG) is the dominant whey globular protein found and secreted in bovine milk. BLG is predominantly dimeric, consisting of two identical unit configurations of 162 residue sequence. BLG provides numerous sites for sulphidryl groups to form.
Although there appears to be no real distinction between curly hair and straight hair substructurally or chemically, there may be a difference in the geometric distribution of orthocortical and paracortical cells or in the shape of the hair follicle. In addition, the differences may be in variable ratio between crystalline and amorphous materials in the hair. Keratin is the principle structural protein of hair, providing its structural integrity. It is composed of eighteen different amino acids and is characterized by the presence of cystine and the absence of hydroxyproline. Keratin is held together by several different kinds of polypeptides bonds such that proteolytic enzymes (i.e., enzymes that break apart, or lyse, protein molecules) do not attack it. The great stability of keratin results from the numerous disulfide bonds of cystine. Hair keratin is insoluble in aqueous salt solutions, weak acids, weak alkalis and neutral solutions. Water can, however, alter its appearance. This is evident when wet hair is set. It will hold the set when it dries, but this change is temporary and will disappear when the hair becomes wet again.
Cystine may account for 24 percent of the total amino acids. The cystine in keratin contains disulfide linkages—the bonds responsible for the strength and structure of natural keratin of hair and nails. Reduction of the disulfide bonds (by thioglycol or some other mild reducing agent) to sulfhydryl groups, results in dissociation of the peptide chains. The presence of these disulfide bonds makes permanent hair conditioning possible. Permanent hair conditioning occurs through a mechanism known as disulfide interchange, a reaction in which cystine-containing proteins covalently bond and form a disulfide link with free sulfhydryl (SH) groups in the hair.
The manufacture of structural soluble keratin-type molecules by cosmetic material suppliers is achieved by the hydrolyzation methods. These methods use very high temperatures and extreme conditions that can convert cystine to cysteic acid (a reaction analogous to the effect of damage in hair). Milk fermentation based on the inoculation of cultures provides a more natural, gentle process and less of a possibility of the conversion of cystine to cysteic acid. Cystine containing proteins can also help protect, strengthen and extend the life of cosmetic chemical hair treatments by reducing “unzipping”, a term used to describe the tendency of reconfigured SH groups to return to the original position. This can occur when one SH group reacts with a neighboring SH group, thereby breaking the S—S linkage to reform the original S—S bond and leaving a different free SH group available. This initiates a chain reaction in which each subsequent free SH group that becomes available reacts with the next S—S bond adjacent to it. Thus, by covalently bonding with residual SH groups left in the hair after a chemical treatment, these proteins are able to “tie-up” or block free SH groups and lessen the incidence of unzipping.
Within the art, it is further known that the bacteria such as Lactobacillus bulgari and Streptococcus thermophilus are necessary ingredients for the creation of yogurt. Other yogurt cultures exhibit marked nutritive and restorative effects and are thus in demand as probiotics in yogurt mixes including, but not limited to, Lactobacillus acidophilius, Lactobacillus reuteri and Bifidobacteria. It has been found that some of these bacteria survive the fermentation process used to form yogurt from milk and provide benefits in addition to those found in the yogurt itself. These bacteria participate in competitive inhibition in the human intestinal tract, where they beat out “bad,” possibly pathogenic microorganisms for nutrients and space. See The Dominant Culture: Yogurt for the Masses, by Kimberly J. Decker, April 2001. It is an aspect of this invention that these bacteria could have similar beneficial effects on hair, which is exposed to numerous bacterial agents throughout a normal day.
The stability of probiotic cultures is also addressed by this invention. In many products containing probiotics that are developed and sold for consumption, active cultures die even before the consumer receives any of the health benefits (i.e., during manufacturing, during storage, or during transport of the finished product). Even if the probiotics stay alive during manufacturing, they must also have sufficient shelf life to be viable when ultimately used. Specifically, probiotics are extremely susceptible to their environment. Such environmental factors as water, oxygen, temperature, and acidity affect the overall viability of these beneficial microorganisms. See, e.g., Patricia Siuta-Cruce and Jacques Goulet, “Improving Probiotic Survival Rates.” Food Technology, October 2001, Vol. 55, No. 10, Pp. 36-42. This problem is addressed in the anhydrous formulation embodiment which is intended to maintain essentially water free conditions to keep the probiotic bacteria more viable prior to usage.
It is the intention of this invention to teach the benefits of using yogurt and components of yogurt in novel hair care compositions that take advantage of the beneficial properties of yogurt, components of yogurt and probiotic bacteria. The compositions taught herein will promote healthy hair 1) by cleaning, repairing and smoothing damaged hair, 2) by promoting a healthy scalp and 3) through a bacterial cleansing of clogged hair follicles. It is suggested by the inventor that the benefits of probiotic bacteria will extend to cleaning and regeneration of the sebacious gland and hair follicle itself by competing with non-beneficial bacteria to promote strong hair growth.